ἀθεμείλιος
From LSJ
Πρόσεχε τῷ ὑποκειμένῳ ἢ τῇ ἐνεργείᾳ ἢ τῷ δόγματι ἢ τῷ σημαινομένῳ. → Look to the essence of a thing, whether it be a point of doctrine, of practice, or of interpretation.
English (LSJ)
ον, without foundation, Ep. word implied by Hsch. ἀθέμηλος· οὐδὸν οὐκ ἔχουσα οὐδὲ θεμέλιον, and ἀθεμίλιος· ἀκροσφαλής, ψεύστης.